Documentation 
Section: http://xmlsoft.org/html/libxml-chvalid.html#xmlIsBlank_ch
This is an example, no macro in chvalid seems to be documented:

Macro: xmlIsBlank_ch

#define xmlIsBlank_ch
Automatically generated by genChRanges.py

Correct version:
This is an example, I don't know what the parameters and return values are, hence the desire for documentation:

Macro: xmlIsBlank_ch( ch )

Returns true if the UTF8 (int) ch is a whitespace character, false otherwise.

Other information:
It was difficult to find the function in the API which checks if a character is whitespace. In general, some documentation of how to work with xmlChar and unicode characters would be nice. Is it correct that xmlChar * is a UTF-8 encoded string?

What is the difference between xmlIsBlankQ and xmlIsBlank_ch? 

The function xmlIsBlankNode in tree.c has a loop:
    while (*cur != 0) {
  if (!IS_BLANK_CH(*cur)) return(0);
  cur++;
    }

Is this correct? What if a xmlChar *string character is more than one byte long? Don't you need to use the xmlGetUTF8Char function for the above loop? Why doesn't the prototype for xmlGetUTF8Char use const xmlChar * instead of "const unsigned char *"? I am confused? Have I misunderstood things completely? Where is this stuff documented?